Regarding the case my solution is the following.
1) Nishino is the culprit.
(Because he was the last to arrive. So for him to manipulate block the tunnel by triggering the avalanche through a bombing suits him best if he is the last one to arrive.
Nishino also similarly blasted/rigged the car park to take the cars out of the equation.
Now to fit the bomb and to get the timing correct to detonate both the mechanisms, there are two solutions,
a) Using a remote.(which is plain wrong given how far the tunnel is.)
b) The person who arrived last.(most likely solution))

2) Wada the first victim was the tallest among the group. So the killing method won't work for anyone else other than Wada(as he is the tallest.)
Wada's body position also indicates that he was standing when the shot had hit him. There would have been more a signs on his clothing if he
fell down and then somebody had shot him.
So the bathroom trap was set up only for Wada. Wada was sent there by the draw, now Nishino was the one who had objected Amuro's method, plus he was the one taking out the chits. On the top of that he once used that method to become the captain back in the days.
So someone in discord suggested that as Wada's name was written in the middlemost/central chit torn out of the page.
So Nishino could have just felt its rough edges and then declared that the next one gets the bathroom and picked it up.

well i think in file 1028 there was a mention that the avalanche that blocked the passage of the tunnel leading out of the isolated church may be artificial-made since one of the police smelled gun-powder. So if that was an artificial avalanche, and if that was indeed the culprit of the murder's doing, then the question would be whether the culprit intended to trap EVERYONE or just the victims? Getting rid of the cars by letting them slide down the cliff and blocking the way of exit with an avalanche... Did the culprit intend to get out alive or not? Maybe the whole church would burn down with everyone inside (dead or alive) if someone like Conan and Amuro aren't there to stop the culprit?

well now who fits that description best? the sushi chef who kept running directly to the Kogoru estate as if in a hurry? Rumi who seemed to have a lot of patience concealing herself like Vermouth? Or the police chief who pressed 'Bourbon' for follow up on previous orders? Then again, which one of the 3 is more likely to make a mistake and lose an eye?

Courtesy of Mak from the DCTP Spoiler Box, back before the 1,027 spoilers came out.

“Life is infinitely stranger than anything which the mind of man could invent. We would not dare to conceive the things which are really mere commonplaces of existence. If we could fly out of that window hand in hand, hover over this great city, gently remove the roofs, and and peep in at the queer things which are going on, the strange coincidences, the plannings, the cross-purposes, the wonderful chains of events, working through generations, and leading to the most outre results, it would make all fiction with its conventionalities and foreseen conclusions most stale and unprofitable.”
“Education never ends... it is a series of lessons, with the greatest for the last.”
― Arthur Conan Doyle, The Complete Adventures of Sherlock Holmes and His Last Bow
"I have decided to stick to love... hate is too great a burden to bear."
— Martin Luther King Jr. (A Testament of Hope: The Essential Writings and Speeches of Martin Luther King, Jr)

Koumei: And arranged to meet my brother Hiromitsu, who had been taken in by relatives in Tokyo,...

Koumei: at a café...

Koumei: That's right, the friend that Hiromitsu brought along...

About time for something like this!

Spoiler:

This is actually pretty fast, for DC standards—the Morofushi connection was revealed only two cases ago, and already, Kōmei suspects that Rei/Tōru is the one who sent him his brother's PSB-related effects, and, at the same time, we have Hyōe (in all probability Rei's/Tōru's boss at the NPA) reaching out to tell him, in particular, something.

“Life is infinitely stranger than anything which the mind of man could invent. We would not dare to conceive the things which are really mere commonplaces of existence. If we could fly out of that window hand in hand, hover over this great city, gently remove the roofs, and and peep in at the queer things which are going on, the strange coincidences, the plannings, the cross-purposes, the wonderful chains of events, working through generations, and leading to the most outre results, it would make all fiction with its conventionalities and foreseen conclusions most stale and unprofitable.”
“Education never ends... it is a series of lessons, with the greatest for the last.”
― Arthur Conan Doyle, The Complete Adventures of Sherlock Holmes and His Last Bow
"I have decided to stick to love... hate is too great a burden to bear."
— Martin Luther King Jr. (A Testament of Hope: The Essential Writings and Speeches of Martin Luther King, Jr)

Koumei: And arranged to meet my brother Hiromitsu, who had been taken in by relatives in Tokyo,...

Koumei: at a café...

Koumei: That's right, the friend that Hiromitsu brought along...

About time for something like this!

Spoiler:

This is actually pretty fast, for DC standards—the Morofushi connection was revealed only two cases ago, and already, Kōmei suspects that Rei/Tōru is the one who sent him his brother's PSB-related effects, and, at the same time, we have Hyōe (in all probability Rei's/Tōru's boss at the NPA) reaching out to tell him, in particular, something.

Spoiler:

Koumei is either as smart as Conan or maybe even smarter than him, so maybe that's why he pretty quickly found out this connection. But I'm glad that Gosho didn't try to drag this for several more chapters. I only wish that at the end of this case he will ask Rei about that connection. It will be funny if Wakita will hear that Rei's conversation with Koumei, and he will turn out to be Rum. Rum finally will find the rat he was searching for. Maybe even that's why he's close to Bourbon - to find out if he's the rat or not (because otherwise it would be pointless for Rum to stick with Bourbon on a church trip).

My dad’s a soldier blue I’ll be a soldier, too
When I grow older you will see me rescue you
I’ll teach you this old song so you can sing along
When I am dead and gone the day won’t be so long.

It will be funny if Wakita will hear that Rei's conversation with Koumei, and he will turn out to be Rum. Rum finally will find the rat he was searching for. Maybe even that's why he's close to Bourbon - to find out if he's the rat or not (because otherwise it would be pointless for Rum to stick with Bourbon on a church trip).

Spoiler:

Kanenori's line in 1,027 about "finding the traitor trying to deceive me" was quite on the nose...

1,031 spoiler pics are now out—and there will now be a 3-weeks-break, so we can expect 1,032 spoilers on April 4th/5th.

“Life is infinitely stranger than anything which the mind of man could invent. We would not dare to conceive the things which are really mere commonplaces of existence. If we could fly out of that window hand in hand, hover over this great city, gently remove the roofs, and and peep in at the queer things which are going on, the strange coincidences, the plannings, the cross-purposes, the wonderful chains of events, working through generations, and leading to the most outre results, it would make all fiction with its conventionalities and foreseen conclusions most stale and unprofitable.”
“Education never ends... it is a series of lessons, with the greatest for the last.”
― Arthur Conan Doyle, The Complete Adventures of Sherlock Holmes and His Last Bow
"I have decided to stick to love... hate is too great a burden to bear."
— Martin Luther King Jr. (A Testament of Hope: The Essential Writings and Speeches of Martin Luther King, Jr)